Okay, so I have the Amulet of Mara and I'm trying to get someone to marry me. He hasn't said anything at all about the amulet and I have helped him out but he still hasn't said anything. Do I just keep talking to him until he notices or something?

if i remember right j'zargo cant be married infact khajiit have no dialog lines in the game regarding marriage i am double checking now for you

Khajiit NPCs cannot be married in any way or form, even with the use of the console. The dialogue options won't be there. However, you can use the console to turn a marriageable NPC of another race into a Khajiit. Khajiit characters can also marry NPCs of other races. from the wiki

Despite not being able to marry J'Zargo by doing his favour you will have the option to use him as a follower. He is (despite Lydia) one of the best in the game as he can reach the highest level (80 something) he also has great sneak skills whereas Lydia sucks and is always giving the game away and triggering traps.

Brianbluewolf is correct that you cannot marry Khajit, don't know why. I would have thought Argonians would be less compatable but there are a few of them you can marry.

I try to keep the game as close to the vanilla version as possible. Only NPC mod I use is the follower fix mod. Too many mods,too many problems. I have kept Lydia as my follower throughout my games though, (annoying as she can be) as I have never got around to using J'Zargo's scrolls.

I try to keep the game as close to the vanilla version as possible. Only NPC mod I use is the follower fix mod. Too many mods,too many problems. I have kept Lydia as my follower throughout my games though, (annoying as she can be) as I have never got around to using J'Zargo's scrolls.